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13 January 2006 <br /> i AGE-NC Project No 98-0497 <br /> Page 2 of 4 <br /> 2 2 GROUND WATER SAMPLE COLLECTION <br /> Prior to the collection of ground water samples,the depth to ground water was re-measured in each <br /> monitoring well to ensure that a minimum 80% of the initial water volume had recharged Water <br /> samples were collected from each well using the inertia pump and dedicated tubing The water was <br /> transferred into one 1-liter amber bottle and three 40-milliliter(ml)volatile organic analysis(VOA) <br /> vials containing 0 5 ml 18%hydrochloric acid solution as a sample preservative After collection, <br /> the samples were labeled and placed in a chilled container for transport under chain of custody to <br /> Cal Tech Environmental Laboratories(CTEL), a California Department of Health Services(DHS)- <br /> certified analytical laboratory in Paramount, California The samples were analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, <br /> respectively) in accordance with EPA Method 8015M, and <br /> • Benzene, toluene, ethylbenzene, and total xylenes (BTEX) and the fuel additive methyl <br /> tertiary-butyl ether(MTBE) by EPA Method 8260B <br /> • 3.0. FINDINGS <br /> Ground water elevation and flow direction were inferred from field data Hydrocarbon-impact to <br /> ground water was assessed by laboratory analysis of the ground water samples <br />' 3 1 GROUND WATER ELEVATION AND GRADIENT <br />' At the time of the September 2005 sampling event, depths to ground water at the site ranged from <br /> 67 83 feet(MW-2)to 68 47 feet(MW-4)below the tops of the well casings Ground water elevation <br /> at the site averaged approximately 43 28 feet below mean sea level (MSL), indicating an average <br />' decrease in ground water elevations of 2 86 feet since the last monitoring event in June 2005 <br /> Ground water elevation data is included in Table 1 <br />' Ground water flow direction was calculated from the ground water elevation data The ground water <br /> was inferred to be flowing toward the northeast at an approximate hydraulic gradient of 0 008 ft/ft <br /> Figure 3 illustrates the contoured ground water elevations as measured on 15 September 2005 <br /> 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br />' The analytical results from the September 2005 round water monitoring event are as follows <br /> . g g <br /> Advanced GcoEnvironmental,Inc <br /> 1 <br />